Disk recording medium, disk manufacturing method, and disk drive apparatus

ABSTRACT

A disk recording medium which can implement a recording method having a high degree of reliability for additional information is disclosed. The disk recording medium has a recording and reproduction region into and from which first data can be recorded and reproduced in accordance with a rewritable or write-once-read-many recording method and from which second data recorded in the form of wobbling of a groove can be reproduced. The second data includes address information and additional information. The additional information of the second data is coded in accordance with a first error correction method, and the coded additional information and the address information are recorded in a state coded in accordance with a second error correction method.

TECHNICAL FIELD

The present invention relates to a disk recording medium such as anoptical disk and a disk production method for producing the diskrecording medium as well as a disk drive apparatus for the diskrecording medium.

BACKGROUND ART

As a technique for recording and reproducing digital data, a datarecording technique is available which uses an optical disk (including amagneto-optical disk) such as, for example, a CD (Compact Disc), an MD(Mini-Disc) and a DVD (Digital Versatile Disc) as a recording medium.The optical disk is a general term for recording media of the typewherein laser light is illuminated upon a disk formed from a thin metalplate protected with plastic and a signal is read from a change inreflected light from the disk.

Optical disks are divided into those of the type which can be used onlyfor reproduction as known as, for example, a CD, a CD-ROM and a DVD-ROMand those of the type on which user data is recordable as known as anMD, a CD-R, a CD-RW, a DVD-R, a DVD-RW, a DVD+RW and a DVD-RAM. Foroptical disk of the recordable type, a magneto-optical recording method,a phase change recording method, a pigment film change recording methodor the like is used to allow recording of data. The pigment film changerecording method is also called write-once recording method and allowsdata recording only once but does not allow re-writing, and therefore,it is suitably used for data storage applications and so forth.Meanwhile, the magneto-optical recording method and the phase changerecording method allow rewriting of data and are utilized for variousapplications beginning with recording of various kinds of contents datasuch as music, videos, games, application programs and so forth.

Further, a high density optical disk called DVR (Data & Video Recording)disk has been developed in recent years and exhibits a significantincrease in capacity.

In order to record data onto a disk which allows recording by themagneto-optical recording method, pigment film change recording methodor phase change recording method, guide means for performing tracking ofa data track is required. To this end, a groove is formed in advance asa pregroove, and the groove or a land (a location of a trapezoidal crosssection positioned between grooves) is used as a data track.

Also it is necessary to record address information in order to allowdata to be recorded at a predetermined position on a data track. Suchaddress information is sometimes recorded by wobbling a groove.

In particular, while a track onto which data is to be recorded is formedin advance, for example, as a pregroove, side walls of the pregroove arewobbled in accordance with address information.

Where side walls of a pregroove are wobbled in this manner, uponrecording or upon reproduction, an address can be read from the wobblinginformation obtained as reflected light information. Thus, even if, forexample, pit data or the like representative of addresses is not formedon the track in advance, data can be recorded or reproduced at a desiredposition.

Where address information is added as a wobbling groove in this manner,for example, if address areas are provided discretely on tracks, then itis unnecessary to record addresses, for example, as pit data, and therecording capacity for actual data can be increased by an amount bywhich the address areas can be eliminated.

It is to be noted that absolute time (address) information representedby such a wobbling groove as described above is called ATIP (AbsoluteTime In Pregroove) or ADIP (Address In Pregroove).

Incidentally, particularly with a rewritable disk, it is necessary torecord, in addition to address information and information (user data)which is recorded and reproduced by a user, attributes of the disk andrecording and reproduction powers, pulse information and so forth asnumerical values for use for control as additional information inadvance on the disk similarly to the address information. For suchadditional information, a high degree of reliability is required.

The reason why a high degree of reliability is required is that, forexample, if attributes or additional information for control is notobtained accurately, then an apparatus on the user side cannot executesuch a control operation for establishing optimum recording conditionscorrectly.

As a method of recording such information on a disk in advance, it isknown to form emboss pits on a disk.

However, if it is intended to achieve high density recording andreproduction onto and from an optical disk, the prerecording method byemboss pits is disadvantageous.

In order to achieve high density recording and reproduction onto andfrom an optical disk, it is necessary to form the groove with a reduceddepth. With a disk produced with a stamper such that a groove and embosspits are formed at a time, it is very difficult to form the groove andthe emboss pits with different depths from each other. Therefore, itcannot be avoided to make the depth of the emboss pits equal to thedepth of the groove.

However, where the depth of the emboss pits is small, there is a problemthat a signal of a good quality cannot be obtained from the emboss pits.

For example, where an optical system including a laser diode of awavelength of 405 nm and an objective lens of NA=0.85 is used and phasechange marks are recorded and reproduced with a track pitch of 0.32 μmand a linear density of 0.12 μm/bit onto and from a disk having a cover(substrate) thickness of 0.1 mm, a capacity of 23 GB (GigaBytes) can berecorded onto and reproduced from an optical disk having a diameter of12 cm.

In this instance, the phase change marks are recorded onto andreproduced from the groove formed spirally on the disk, and in order tosuppress the medium noise to achieve high density, preferably the depthof the groove is set to approximately 20 nm, that is, λ/13 to x/12 withrespect to the wavelength λ.

On the other hand, in order to obtain a signal of a good quality fromthe emboss pits, preferably the depth of the emboss pits is λ/8 to λ/4.After all, a good solution to a common depth to the groove and theemboss pits cannot be obtained.

From such a situation as just described, a method of recording necessaryadditional information in advance in place of emboss pits is demanded.Besides, it is demanded to record the additional information with a highdegree of reliability.

DISCLOSURE OF INVENTION

Taking the situations described above into consideration, it is anobject of the present invention to record additional information to berecorded in advance together with address information appropriately andwith a high degree of reliability.

In order to attain the object described above, according to the presentinvention, a disk recording medium is configured such that the diskrecording medium has a recording and reproduction region into and fromwhich first data can be recorded and reproduced in accordance with arewritable or write-once-read-many recording method and from whichsecond data recorded in the form of wobbling of a groove can bereproduced, and that the second data includes address information andadditional information and the additional information is coded inaccordance with a first error correction method, and the codedadditional information and the address information are recorded in astate coded in accordance with a second error correction method.

The first error correction method is same as the error correction methodused for the first data.

The additional information is error correction coded such that, to theadditional information of a unit of m smaller than a code length n inerror correction coding of the first data, m-n dummy data are added soas to have a code length equal to n.

The additional information is recorded at least in a lead-in zone in therecording and reproduction region.

According to the present invention, a disk production method for a diskrecording medium having a recording and reproduction region into andfrom which first data is to be recorded and reproduced in accordancewith a rewritable or write-once-read-many recording method is configuredsuch that additional information is coded in accordance with a firsterror correction method and the coded additional information and addressinformation are coded in accordance with a second error correctionmethod, and a groove wobbled based on the second data is formed spirallyto form the recording and reproduction region.

The first error correction method is same as the error correction methodused for the first data.

The additional information is error correction coded such that, to theadditional information of a unit of m smaller than a code length n inerror correction coding of the first data, m-n dummy data are added soas to have a code length equal to n.

The additional information is recorded at least in a lead-in zone in therecording and reproduction region.

According to the present invention, a disk drive apparatus whichperforms recording or reproduction onto or from the disk recordingmedium described above is configured such that the disk drive apparatusincludes readout means for reading out the second data from the wobbledgroove of the disk recording medium, address decoding means forperforming error correction decoding in accordance with the second errorcorrection method for the second data read out by the readout means toobtain the address information and the additional information coded inaccordance with the first error correction method, and additionalinformation decoding means for performing error correction decoding inaccordance with the first error correction method for the additionalinformation coded in accordance with the first error correction methodand obtained by the address decoding means.

The first error correction method is same as the error correction methodused for the first data, and the additional information decoding meansfurther performs error correction decoding and error correction codingfor the first data.

The additional information decoding means adds, to the additionalinformation of a unit of m smaller than a code length n in errorcorrection coding of the first data, m-n dummy data to perform errorcorrection decoding for the data having a code length equal to n.

The additional information is obtained from the second data read outfrom a lead-in zone in the recording and reproduction region by thereadout means.

In particular, according to the present invention, when the additionalinformation is recorded in advance onto a rewritable orwrite-once-read-many disk of a large capacity, the additionalinformation is recorded by wobbling a groove together with addressinformation. Further, the additional information is coded in accordancewith the first error correction method, and the coded additionalinformation and the address information are coded in accordance with thesecond error correction method to obtain second data. Then, the grooveis wobbled with the second data. Consequently, the additionalinformation can be recorded in the form of a wobbling groove togetherwith the address information. Further, the additional information iserror correction coded dually in accordance with the first and seconderror correction methods.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view illustrating a groove of a disk of anembodiment of the present invention;

FIG. 2 is a schematic view illustrating wobbling of the groove of thedisk of the embodiment;

FIG. 3 is a schematic view illustrating a wobble signal to which MSKmodulation and HMW modulation of the embodiment are applied;

FIGS. 4A to 4E are diagrammatic views illustrating the MSK modulation ofthe embodiment;

FIG. 5 is a block diagram of an MSK demodulation circuit fordemodulating an MSK modulated wobble signal of the embodiment;

FIG. 6 is a waveform diagram of an inputted wobble signal and asynchronous detection output signal of the embodiment;

FIG. 7 is a waveform diagram of an integrated output value of asynchronous detection output signal of an MSK stream of the embodiment,a hold value of the integrated output value and MSK demodulatedmodulation object data;

FIGS. 8A to 8C are waveform diagrams illustrating HMW modulation of theembodiment;

FIG. 9 is a block diagram of an HMW demodulation circuit fordemodulating an HMW modulated wobble signal of the embodiment;

FIG. 10 is a waveform diagram of a reference carrier signal of theembodiment, modulation object data and a second order harmonic signalwaveform generated in response to the modulation object data;

FIG. 11 is a waveform diagram of a generated HMW stream of theembodiment;

FIGS. 12A and 12B are waveform diagrams of a synchronous detectionoutput signal of an HMW stream of the embodiment, an integrated outputvalue of the synchronous detection output signal, a hold value of theintegrated output value and HMW demodulated modulation object data;

FIG. 13 is a schematic view showing a disk layout of the embodiment;

FIGS. 14A and 14B are schematic views illustrating wobbling in a PB zoneand an RW zone of the embodiment;

FIG. 15 is a diagrammatic view illustrating a modulation method ofprerecorded information of the embodiment;

FIG. 16 is a schematic view illustrating an ECC structure of a phasechange mark of the embodiment;

FIG. 17 is a schematic view illustrating an ECC structure of prerecordedinformation of the embodiment;

FIGS. 18A and 18B are diagrammatic views illustrating a frame structureof phase change marks and prerecorded information of the embodiment;

FIGS. 19A and 19B are diagrammatic views illustrating a relationshipbetween a RUB and an address unit of the disk of the embodiment and abit block which forms an address unit;

FIG. 20 is a diagrammatic view illustrating a sync part of an addressunit of the embodiment;

FIGS. 21A and 21B are diagrammatic views illustrating monotone bits inthe sync part of the embodiment and modulation object data;

FIGS. 22A and 22B are diagrammatic views illustrating a first sync bitin the sync part of the embodiment and modulation object data;

FIGS. 23A and 23B are diagrammatic views illustrating a second sync bitin the sync part of the embodiment and modulation object data;

FIGS. 24A and 24B are diagrammatic views illustrating a third sync bitin the sync part of the embodiment and modulation object data;

FIGS. 25A and 25B are diagrammatic views illustrating a fourth sync bitin the sync part of the embodiment and modulation object data;

FIG. 26 is a diagrammatic view illustrating a bit configuration of adata part in the address unit of the embodiment;

FIGS. 27A to 27C are diagrammatic views illustrating a signal waveformof ADIP bits representative of a bit “1” of the data part of theembodiment and modulation object data;

FIGS. 28A to 28C are diagrammatic views illustrating a signal waveformof ADIP bits representative of a bit “0” of the data part of theembodiment and modulation object data;

FIG. 29 is a view illustrating an address format of the embodiment;

FIG. 30 is a view illustrating address information contents by ADIP bitsof the embodiment;

FIG. 31 is a block diagram of an address demodulation circuit of theembodiment;

FIGS. 32A to 32E are diagrams illustrating control timings of theaddress demodulation circuit of the embodiment;

FIGS. 33A to 33C are waveform diagrams of signals when HMW demodulationis performed by the address demodulation circuit of the embodiment;

FIGS. 34A to 34C are waveform diagrams of different signals when HMWdemodulation is performed by the address demodulation circuit of theembodiment;

FIG. 35 is a view illustrating disk information of the embodiment;

FIG. 36 is a diagrammatic view illustrating an ECC format for main dataof the embodiment;

FIG. 37 is a diagrammatic view illustrating an ECC format for diskinformation of the embodiment;

FIG. 38 is a block diagram of a disk drive apparatus of the embodiment;and

FIG. 39 is a block diagram of a mastering apparatus of the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, an optical disk as an embodiment of the presentinvention is described, and a disk drive apparatus (recording andreproduction apparatus) which performs recording and reproduction ontoand from the optical disk and a mastering apparatus used for productionof the optical disk are described. The description is given in thefollowing order.

-   1. Wobbling System of the Disk    -   1-1. General Description of the Wobbling System    -   1-2. MSK Modulation    -   1-3. HMW Modulation    -   1-4. Summary-   2. Application to a DVR    -   2-1. Physical Characteristics of a DVR Disk    -   2-2. ECC Format of the Data    -   2-3. Address Format        -   2-3-1. Relationship Between Recording and Reproduction data            and Addresses        -   2-3-2. Sync Part        -   2-3-3. Data Part        -   2-3-4. Contents of the Address Information        -   2-4. Address Demodulation Circuit-   3. ECC Format of the Disk Information-   4. Disk Drive Apparatus-   5. Disk Production Method    1. Wobbling System of the Disk

1-1. General Description of the Wobbling System

An optical disk 1 of an embodiment of the present invention has a grooveGV serving as recording tracks formed thereon as shown in FIG. 1. Thegroove GV is formed spirally from the inner circumference side to theouter circumference side. Therefore, if a cross section of the opticaldisk 1 in a radial direction is taken, then a convex land L and theconcave groove GV are formed alternately as seen in FIG. 2.

The groove GV of the optical disk 1 is formed in a wobbled state withrespect to a tangential direction as seen in FIG. 2. The wobbling of thegroove GV has a shape corresponding to a wobble signal. Therefore, anoptical disk drive can reproduce the wobble signal by detecting theopposite edge positions of the groove GV from reflected light of a laserspot LS illuminated upon the groove GV and extracting variationcomponents of the opposite edge positions with respect to a disk radiusdirection when the laser spot LS moves along a recording track.

The wobble signal includes modulated address information (a physicaladdress and other additional information and so forth) of the recordingtrack at the recording position. Therefore, an optical disk drive canperform address control and so forth upon recording or reproduction ofdata by demodulating the address information and so forth from thewobble signal.

It is to be noted that, while the embodiment of the present inventiondescribed below is directed to an optical disk to which groove recordingis applied, the present invention can be applied not only to such anoptical disk of the groove recording type but also to an optical disk towhich land recording wherein data is recorded on a land is applied.Further, the present invention can be applied also to an optical disk ofthe land and groove recording type wherein data is recorded on both of agroove and a land.

Here, in the optical disk 1 of the present embodiment, two modulationmethods are used to modulate address information on the wobble signal.One of them is an MSK (Minimum Shift Keying) modulation method. Theother is a method wherein an even-numbered order harmonic signal isadded to a carrier signal of a sine wave and the polarity of theharmonic signal is changed in accordance with the sign of modulationobject data to modulate the modulation object data. In the following,the modulation method wherein an even-numbered order harmonic signal isadded to a carrier signal of a sign wave and the polarity of theharmonic signal is varied in accordance with the sign of modulationobject data to modulate the modulation object data is referred to as HMW(HarMonic Wave) modulation.

In the optical disk 1 of the present embodiment, a block in which areference carrier signal waveform of a sine wave of a predeterminedfrequency appears continuously for a predetermined period is formed asshown in FIG. 3. In the block, a wobble signal is generated whichincludes an MSK modulation part in which MSK modulated addressinformation is inserted and an HMW modulation part in which HMWmodulated address information is inserted. In other words, MSK modulatedaddress information and HMW modulated address information are insertedat different positions in the block. Further, one of two carrier signalseach in the form of a sine wave used for the MSK modulation and acarrier signal for the HMW modulation are used as a reference carriersignal described hereinabove. Further, the MSK modulation part and theHMW modulation part are disposed at different positions in the block,and a reference carrier signal for more than one period is disposedbetween the MSK part and the HMW part.

It is to be noted that a portion in which data is not modulated and onlya frequency component of a reference carrier signal appears ishereinafter referred to as monotone wobbles. Further, in the followingdescription, the sine wave signal used as a reference carrier signal isCos(ωt). Furthermore, one period of the reference carrier signal isreferred to as one wobble period. Further, the frequency of thereference carrier signal is fixed from the inner circumference to theouter circumference of the optical disk 1 and is defined in accordancewith a relationship with the linear velocity when a laser spot movesalong the recording track.

1-2. MSK Modulation

In the following, the modulation methods of the MSK modulation and theHMW modulation are described in more detail. Here, the modulation methodof address information for which the MSK modulation method is used isdescribed first.

The MSK modulation is a kind of FSK (Frequency Shift Keying) modulationhaving a continuous phase in which the modulation index is 0.5. The FSKmodulation is a method of modulating codes of “0” and “1” of modulationobject data in a corresponding relationship to two carrier signals of afrequency f1 and another frequency f2. In particular, the FSK modulationis a method wherein, if the modulation object data is “0”, then a sinewaveform of the frequency f1 is outputted, but if the modulation objectdata is “1”, then another sine wave of the frequency f1 is outputted.Further, in the case of the FSK modulation wherein the phases continue,the phases of two carrier signals continue at a changeover timing of thesign of modulation object data.

In the FSK modulation, a modulation index m is defined. The modulationindex m is defined bym=|f1−f2|Twhere T is the transmission rate of the modulation object data (time ofa 1/smallest code length). The phase-continuous FSK modulation where mis 0.5 is called MSK modulation.

In the optical disk 1, the code length L of modulation object data to beMSK modulated is equal to twice the wobble period as seen in FIGS. 4Aand 4B. It is to be noted that the code length L of modulation objectdata may be any length only if it is equal to or greater than twice thewobble period and equal to an integral number of times the wobbleperiod. Further, one of the two frequencies for use with the MSKmodulation is set equal to that of the reference carrier signal whilethe other is set to 1.5 times the reference carrier frequency. In otherwords, one of the signal waveforms for use with the MSK modulation isCos(ωt) or −Cos(ωt) while the other is Cos(1.5ωt) or −Cos(1.5ωt).

In order to insert modulation object data into a wobble signal of theoptical disk 1 in accordance with the MSK modulation method, adifferential coding process is performed for a data stream of themodulation object data in a clock unit corresponding to the wobbleperiod as seen in FIG. 4C. In particular, the stream of the modulationobject data and delayed data obtained by delaying the modulation objectdata by one period of the reference carrier signal are differentiallyoperated. The data obtained by the differential coding process isreferred to as precode data.

Then, such precode data are MSK modulated to generate an MSK stream. TheMSK stream has such a signal waveform that, as shown in FIG. 4D, whenthe precode data is “0”, the MSK stream exhibits a waveform (Cos(ωt)) ofthe frequency equal to that of the reference carrier or an invertedwaveform (−Cos(ωt)) of the waveform, but when the precode data is “1”,the MSK stream exhibits a waveform (Cos(1.5ωt)) of a frequency equal to1.5 times that of the reference carrier or an inverted waveform(−Cos(1.5ωt)) of the waveform. Accordingly, if the data string of themodulation object data has a pattern of “010” as seen in FIG. 4B, thenthe signal waveform of the MSK stream has waveforms of Cos(ωt), Cos(ωt),Cos(1.5ωt), −Cos(ωt), −Cos(1.5ωt) and Cos(ωt) for each one wobble periodas seen in FIG. 4E.

In the optical disk 1, address information is modulated on the wobblesignal by converting the wobble signal into such an MSK stream asdescribed above.

Here, where modulation object data is differentially coded and then MSKmodulated as described above, synchronous detection of the modulationobject data is possible. The reason why synchronous detection ispossible in this manner is such as follows.

In differentially coded data (precode data), the bit rises (to “1”) at acode changing point of the modulation object data. Since the code lengthof the modulation object data is equal to or greater than twice thewobble period, the reference carrier signal (Cos(ωt)) or the invertedsignal (−Cos(ωt)) of the carrier signal is inserted in the latter halfof the code length of the modulation object data without fail. If a bitof the precode data exhibits “1”, then a waveform of a frequency equalto 1.5 times that of the reference carrier signal is inserted, and atthe code changeover point, the waveforms are connected to each otherwith the phases thereof adjusted to each other. Accordingly, if themodulation object data is “0”, then the reference carrier signalwaveform (Cos(ωt)) is exhibited, but if the modulation object data is“1”, then the inverted signal waveform (−Cos(ωt)) of it is exhibited.Since the synchronous detection output exhibits a positive value if thephase is same as that of the carrier signal but exhibits a negativevalue if the phase is reverse to that of the carrier signal, if such anMSK modulated signal as described above is synchronously detected withthe reference carrier signal, then the modulation object data can bedemodulated.

It is to be noted that, since the MSK modulation adjusts the phase ateach code changeover point in modulation, a delay is generated beforethe level of the synchronous detection signal is inverted. Therefore,when such an MSK modulated signal as described above is to bedemodulated, for example, an integration window for the synchronousdetection output is delayed by a ½ wobble period so that an accuratedetection output may be obtained.

FIG. 5 shows an MSK demodulation circuit for demodulating modulationobject data from such an MSK stream as described above.

Referring to FIG. 5, the MSK demodulation circuit 10 includes a PLLcircuit 11, a timing generator (TG) 12, a multiplier 13, an integrator14, a sample/hold (SH) circuit 15, and a slice circuit 16.

A wobble signal (MSK modulated stream) is inputted to the PLL circuit11. The PLL circuit 11 detects edge components from the wobble signalinputted thereto to generate a wobble clock synchronized with thereference carrier signal (Cos(ωt)). The generated wobble clock issupplied to the timing generator 12.

The timing generator 12 generates a reference carrier signal (Cos(ωt))synchronized with the wobble signal inputted thereto. Further, thetiming generator 12 generates a clear signal (CLR) and a hold signal(HOLD) from the wobble clock. The clear signal (CLR) is a signalgenerated at a timing delayed by a ½ wobble period from a start edge ofa data clock of the modulation object data whose minimum code length isequal to twice the wobble period. Meanwhile, the hold signal (HOLD) is asignal generated at a timing delayed by a ½ wobble period from an endedge of the data clock of the modulation object data. The referencecarrier signal (Cos(ωt)) generated by the timing generator 12 issupplied to the multiplier 13. The clear signal (CLR) generated by thetiming generator 12 is supplied to the integrator 14. The hold signal(HOLD) generated by the timing generator 12 is supplied to thesample/hold circuit 15.

The multiplier 13 multiplies the wobble signal inputted thereto by thereference carrier signal (Cos(ωt)) to perform a synchronous detectionprocess. The synchronously detected output signal is supplied to theintegrator 14.

The integrator 14 performs an integration process for the signalsynchronously detected by the multiplier 13. It is to be noted that theintegrator 14 clears its integrated value to zero at a generation timingof the clear signal (CLR) generated by the timing generator 12.

The sample/hold circuit 15 samples the integrated output value of theintegrator 14 at a generation timing of the hold signal (HOLD) generatedby the timing generator 12 and holds the sampled value until a next holdsignal (HOLD) is generated.

The slice circuit 16 binarizes the value held by the sample/hold circuit15 using the origin (0) as a threshold value and outputs the binarizedvalue with the sign reversed.

Then, the output signal of the slice circuit 16 makes demodulatedmodulation object data.

FIGS. 6 and 7 show a wobble signal (MSK stream) generated by the MSKmodulation described above of modulation object data of a data string of“0100” and output signal waveforms from the circuits of the MSKdemodulation circuit 10 when the wobble signal is inputted to the MSKdemodulation circuit 10, respectively. It is to be noted that the axisof abscissa (n) of FIGS. 6 and 7 indicates the period number of thewobble period. FIG. 6 shows the inputted wobble signal (MSK stream) andthe synchronous detection output signal (MSK×Cos(ωt)) of the wobblesignal. Meanwhile, FIG. 7 shows the integrated output value of thesynchronous detection output signal, the hold value of the integratedoutput value, and the demodulated modulation object data outputted fromthe slice circuit 16. It is to be noted that the reason why thedemodulated modulation object data outputted from the slice circuit 16is delayed is a processing delay of the integrator 14.

As described above, where modulation object data is differentially codedand then MSK modulated in such a manner as described above, synchronousdetection of the modulation object data is possible.

In the optical disk 1, address information MSK modulated in such amanner as described above is included in the wobble signal. Whereaddress information is MSK modulated and inclined in the wobble signalin this manner, the amount of high frequency components included in thewobble signal is reduced. Accordingly, accurate address detection can beanticipated. Further, since the MSK modulated address information isinserted into monotone wobbles, crosstalk which the address informationmay apply to adjacent tracks can be reduced, and consequently, the S/Nratio can be improved. Further, in the present optical disk 1, since MSKmodulation object data can be synchronously detected and demodulated,demodulation of the wobble signal can be performed accurately andsimply.

1-3. HMW Modulation

How, an address information modulation method which uses the HMWmodulation is described.

The HMW modulation is a modulation method wherein an even-numbered orderharmonic signal is added to a carrier signal of a sign wave and thepolarity of the harmonic signal is varied in accordance with the sign ofmodulation object data to modulate codes.

In the optical disk 1, the carrier signal for the HMW modulation is asignal of the same frequency and the same phase as those of thereference carrier signal (Cos(ωt)) which is the carrier signal for theMSK modulation. As an even-numbered order harmonic signal to be added,Sin(2ωt) and −Sin(2ωt) which are second order harmonics of the referencecarrier signal (Cos(ωt)) are used, and the amplitude of them is set toan amplitude of −12 dB with respect to the amplitude of the referencecarrier signal. The minimum code length of modulation object data is setto twice the wobble period (period of the reference carrier signal).

Then, when the code of the modulation object data is “1”, Sin(2ωt) isadded to the carrier signal, but when the code of the modulation objectdata is “0”, −Sin(2ωt) is added to the carrier signal to performmodulation.

Signal waveforms where the wobble signal is modulated in accordance withsuch a method as described above are illustrated in FIGS. 8A to 8C. FIG.8A shows a signal waveform of the reference carrier signal (Cos(ωt))FIG. 8B shows a signal waveform of the reference carrier signal(Cos(ωt)) to which Sin(2ωt) is added, that is, a signal waveform whenthe modulation object data is “1”. FIG. 8C shows a signal waveform ofthe reference carrier signal (Cos(ωt)) to which −Sin(2ωt) is added, thatis, a signal waveform when the modulation object data is “0”.

It is to be noted that, while, in the optical disk 1, the harmonicsignal to be applied to the carrier signal is a second order harmonic,it is not limited to the second order harmonic, but any signal may beadded if it is an even-numbered order harmonic. Further, while, in theoptical disk 1, only a second order harmonic is added, a plurality ofharmonic signals may be applied simultaneously such that both of asecond order harmonic and a fourth order harmonic are addedsimultaneously.

Here, where only positive and negative even-numbered order harmonicsignals are added to the reference carrier signal in this manner, fromthe characteristic of the generated waveform, it is possible tosynchronously detect the generated waveform with the harmonic signalsand integrates the synchronous detection output for a period of time ofthe code length of the modulation object data to demodulate themodulation object data.

FIG. 9 shows an HMW demodulation circuit for demodulating modulationobject data from a wobble signal HMW modulated in such a manner asdescribed above.

Referring to FIG. 9, the HMW demodulation circuit 20 includes a PLLcircuit 21, a timing generator (TG) 22, a multiplier 23, an integrator24, a sample/hold (SH) circuit 25 and a slice circuit 26.

A wobble signal (HMW modulated stream) is inputted to the PLL circuit21. The PLL circuit 21 detects edge components from the wobble signalinputted thereto to generate a wobble clock synchronized with thereference carrier signal (Cos(ωt)). The generated wobble clock issupplied to the timing generator 22.

The timing generator 22 generates a second order harmonic signal(Sin(2ωt)) synchronized with the wobble signal inputted thereto.Further, the timing generator 22 generates a clear signal (CLR) and ahold signal (HOLD) from the wobble clock. The clear signal (CLR) is asignal generated at a timing of a start edge of a data clock of themodulation object data whose minimum code length is equal to twice thewobble period. Meanwhile, the hold signal (HOLD) is a signal generatedat a timing of an end edge of the data clock of the modulation objectdata. The second order harmonic signal (Sin(2ωt)) generated by thetiming generator 22 is supplied to the multiplier 23. The clear signal(CLR) generated by the timing generator 22 is supplied to the integrator24. The hold signal (HOLD) generated by the timing generator 22 issupplied to the sample/hold circuit 25.

The multiplier 23 multiplies the wobble signal inputted thereto by thesecond order harmonic signal (Sin(2ωt)) to perform a synchronousdetection process. The synchronously detected output signal is suppliedto the integrator 24.

The integrator 24 performs an integration process for the signalsynchronously detected by the multiplier 23. It is to be noted that theintegrator 24 clears its integrated value to zero at a generation timingof the clear signal (CLR) generated by the timing generator 22.

The sample/hold circuit 25 samples the integrated output value of theintegrator 24 at a generation timing of the hold signal (HOLD) generatedby the timing generator 22 and holds the sampled value until a next holdsignal (HOLD) is generated.

The slice circuit 26 binarizes the value held by the sample/hold circuit25 using the origin (0) as a threshold value and outputs the sign of thebinarized value.

Then, the output signal of the slice circuit 26 makes demodulatedmodulation object data.

FIGS. 10, 11 and 12A to 12B show signal waveforms used for the HMWmodulation described above of modulation object data of a data string of“1010”, a wobble signal generated by the HMW modulation and outputsignal waveforms from the circuits of the HMW demodulation circuit 20when the wobble signal is inputted to the HMW demodulation circuit 20,respectively. It is to be noted that the axis of abscissa (n) of FIGS.10 to 12B indicates the period number of the wobble period. FIG. 10shows the reference charier signal (Cos(ωt)), the modulation object dataof the data string of “1010”, and the second order harmonic signal(±Sin(2ωt), −12 dB) generated in response to the modulation object data.FIG. 11 shows the generated wobble signal (HMW stream). FIG. 12A showsthe synchronous detection output signal (HMW×Sin(2ωt)) of the wobblesignal. FIG. 12B shows the integrated output value of the synchronousdetection output signal, the hold value of the integrated output value,and the demodulated modulation object data outputted from the slicecircuit 26. It is to be noted that the reason why the demodulatedmodulation object data outputted from the slice circuit 26 is delayed isa processing delay of the integrator 14.

As described above, where modulation object data is differentially codedand then HMW modulated in such a manner as described above, synchronousdetection of the modulation object data is possible.

In the optical disk 1, address information HMW modulated in such amanner as described above is included in the wobble signal. Whereaddress information is HMW modulated and inclined in the wobble signalin this manner, frequency components can be restricted and the amount ofhigh frequency components included in the wobble signal can be reduced.Consequently, the S/N ratio of the demodulation output of the wobblesignal can be improved, and accurate address detection can beanticipated. Further, also the modulation circuit can be formed from acarrier signal generation circuit, a generation circuit for a harmonicof the carrier signal and an addition circuit for output signals of thetwo generation circuits, and is simplified significantly. Further, sincehigh frequency components of the wobble signal are reduced, alsomastering upon formation of optical disks is facilitated.

Furthermore, since HMW modulated address information is inserted intomonotone wobbles, the crosstalk to be applied to adjacent tracks can bereduced, and consequently, the S/N ratio can be improved. Further, inthe present optical disk 1, since HMW modulated data can besynchronously detected and demodulated, demodulation of the wobblesignal can be performed accurately and simply.

1-4. Summary

As described above, in the optical disk 1 of the present embodiment, anMSK modulation method and an HMW modulation method are adopted as amodulation method for address information on a wobble signal. Further,in the optical disk 1, a sine wave signal (Cos(ωt)) of an equalfrequency is used for both of one of frequencies used for the MSKmodulation method and a carrier frequency used for the HMW modulation.Furthermore, monotone wobbles in which only the carrier signal (Cos(ωt))on which no data is modulated is included is provided between themodulation signals in the wobble signal.

In the optical disk 1 of the present embodiment having such aconfiguration as described above, since the signal of the frequency usedfor the MSK modulation and the harmonic signal used for the HMWmodulation are in a relationship wherein they do not interfere with eachother, detection of each of the signals is not influenced by modulationcomponents of the other signal. Therefore, the address informationrecorded in accordance with the two modulation methods can be detectedwith certainty. Accordingly, the accuracy in control of the trackposition and so forth upon recording and/or reproduction of the opticaldisk can be improved.

Further, if the address information recorded in the MSK modulation andthe address information recorded in the HMW modulation have the samedata contents, then the address information can be detected with ahigher degree of certainty.

Further, since one of frequencies used in the MSK modulation method andthe carrier frequency used in the HMW modulation are set to a sine wavesignal (Cos(ωt)) of the same frequency and besides the MSK modulationand the HMW modulation are performed at different portions in the wobblesignal, upon modulation, for example, a harmonic signal may be added tothe wobble signal after it is MSK modulated at the position of wobblesto be HMW modulated. Thus, the two modulations can be performed verysimply. Further, where the MSK modulation and the HMW modulation areperformed at different portions of a wobble signal and at least amonotone wobble for one period is included between the two portions, adisk can be produced with a higher degree of accuracy, and demodulationof an address can be performed with certainty.

2. Application to a DVR

2-1. Physical Characteristics of a DVR Disk

Now, an application of the address format to a high density optical diskcalled DVR (Data & Video Recording) is described.

First, an example of physical parameters of a DVR disk to which thepresent address format is applied is described. It is to be noted thatthe physical parameters are an example, and it is possible to apply awobble format described below to another optical disk of differentphysical characteristics.

An optical disk to be formed as a DVR disk of the present example is anoptical disk onto which data is recorded in accordance with a phasechange method, and as the disk size, the diameter is 120 mm. Further,the disk thickness is 1.2 mm. In other words, from the parameters given,the outer shape of the optical disk is similar to that of a disk of theCD (Compact Disc) type or a disk of the DVD (Digital Versatile Disc)type.

The laser wavelength for recording/reproduction is 405 nm, and a bluelaser is used. The NA of the optical system is 0.85.

The track pitch of tracks on which phase change marks are recorded is0.32 μm, and the linear density is 0.12 μm. A data block of 64 KB isused as a recording/reproduction unit, and the format efficiency isapproximately 82%. Thus, the disk of the diameter of 12 cm achieves auser data capacity of 23.3 Gbytes.

As described above, the groove recording method is used for the datarecording.

FIG. 13 shows a layout (regional configuration) of the entire disk.

As regions on the disk, a lead-in zone, a data zone and a lead-out zoneare disposed from the inner circumference side.

Further, from a point of view of a regional configuration regardingrecording and reproduction, the inner circumference side of the lead-inzone is a PB zone (region only for reproduction), and the region fromthe outer circumference side of the lead-in zone to the lead-out zone isan RW (region for recording and reproduction).

The lead-in zone is positioned on the inner side from a radius of 24 mm.The range from 21 to 22.2 mm in radius is a BCA (Burst Cutting Area).The BCA has a unique ID unique to the disk recording medium recorded ina recording method of burning out the recording layer. In short,recording marks are formed in a concentrically juxtaposed relationshipto form bar code-like recorded data.

The range from 22.2 to 23.1 mm in radius is a prerecorded data zone.

In the prerecorded data zone, disk information such as recording andreproduction power conditions, information for use for copy protectionand other necessary information (prerecorded information) is recorded inadvance by wobbling of the groove spirally formed on the disk.

The kinds of information mentioned are information only forreproduction, and the BCA and the prerecorded data zone make the PB zone(region only for reproduction) described hereinabove.

While the prerecorded data zone includes, for example, copy protectioninformation as the prerecorded information therein, the copy protectioninformation is used, for example, to perform the following.

In an optical disk system according to the present embodiment,registered drive apparatus makers and disk makers can carry out thebusiness, and a mediakey or a drivekey representing such registration isprovided.

If hacking occurs, then the drivekey or mediakey is recorded as copyprotection information. A medium or a drive having the mediakey or thedrivekey can be disabled from recording and reproduction based on theinformation.

In the lead-in zone, a test write area OPC and a defect management areaDMA are provided within the range from 23.1 to 24 mm in radius.

The test write area OPC is used for test writing upon setting ofrecording and/or reproduction conditions of phase change marks such aslaser powers upon recording/reproduction.

The defect management area DMA is provided to record and reproduceinformation for managing defect information on the disk thereon andtherefrom.

The range from 24.0 to 58.0 mm in radius is set as the data zone. Thedata zone is a region into and from which user data are actuallyrecorded and reproduced as phase change marks.

The range from 58.0 to 58.5 mm in radius is set as the lead-out zone.The lead-out zone includes a defect management area similar to that inthe lead-in zone and is further used as a buffer area for allowing anoverrun upon seeking.

The range from 23.1 mm in diameter, that is, the test write area, to thelead-out zone is the RW zone (recording and reproduction region) intoand from which phase change marks are recorded and reproduced.

FIGS. 14A and 14B show a manner of the tracks in the RW zone and the PBzone, respectively. FIG. 14A shows wobbling of the groove in the RW zonewhile FIG. 14B shows wobbling of the groove in the prerecorded zone ofthe PB zone.

In the RW zone, address information (ADIP) is formed in advance bywobbling the groove formed spirally on the disk in order to allowtracking.

Into and from the groove on which the address information is formed,information is recorded and reproduced as phase change marks.

As shown in FIG. 14A, the groove in the RW zone, that is, the groovetracks on which the ADIP address information is formed, have a trackpitch TP=0.32 μm.

On the tracks, recording marks each in the form of a phase change markare recorded. The phase change marks are recorded in a linear density of0.12 μm/bit, 0.08 μm/ch bit in accordance with the RLL (1,7) PPmodulation method (RLL; Run Length Limited, PP: Parity Preserve/Prohibitrmtr (repeated minimum transition runlength)) or a like method.

Where a 1 ch bit is 1T, the mark length ranges from 2T to 8T, and thesmallest mark length is 2T.

The address information is recorded in a wobbling period of 69T and awobbling amplitude WA of approximately 20 nm(p-p).

The address information and the phase change marks are recorded suchthat the wavelength bands thereof do not overlap with each other so thatthey may not have an influence on detection thereof.

The CNR (carrier noise ratio) of the wobbling of the address informationis 30 dB after recording where the band width is 30 KHz, and the addresserror rate is lower than 1×10⁻³ including the influence of a steppingmovement (a skew of the disk, defocusing, a disturbance and so forth).

Meanwhile, the tracks formed from the groove in the PB zone of FIG. 14Bhave a greater track pitch and a greater wobbling amplitude than thetracks formed from the groove in the RW zone of FIG. 14A.

In particular, the track pitch TP is 0.35 μm, and the wobbling period is36T and the wobbling amplitude WA is approximately 40 nm(p-p). The factthat the wobbling period is 36T signifies that the recording lineardensity of prerecorded information is higher than the recording lineardensity of the ADIP information. Further, since the shortest phasechange mark is 2T, the recording linear density of the prerecordedinformation is lower than the recording linear density of the phasechange marks.

No phase change mark is recorded onto the tracks in the PB zone.

The wobbling waveform is formed in a sine waveform in the RW zone, butmay be recorded in a sine waveform or a rectangular waveform in the PBzone.

It is known that, if the phase change marks have a signal quality of aCNR of approximately 50 dB where the band width is 30 KHZ, then byrecording and reproducing data with ECCs (error correction codes) addedthereto, a symbol error rate lower than ×10⁻¹⁶ after error correctioncan be achieved. Therefore, the phase change marks can be used forrecording and reproduction of data.

The CNR of the wobbles regarding the ADIP address information is 35 dBin a non-recorded state of phase change marks where the band width is 30KHz.

Such a degree of signal quality as just described is sufficient for theaddress information if interpolation protection based on continuitydiscrimination is performed. However, for the prerecorded information tobe recorded in the PB zone, a degree of signal quality higher than theCNR of 50 dB equal to that of the phase change marks should be secured.Therefore, in such a PB zone as shown in FIG. 14B, a groove physicallydifferent from the groove in the RW zone is formed.

First, by making the track pitch wider, the crosstalk from adjacenttracks can be suppressed, and by doubling the wobble amplitude, the CNRcan be improved by +6 dB.

Furthermore, by using a rectangular wave as the wobble waveform, the CNRcan be improved by approximately +2 dB.

The totaling CNR is 43 dB.

The recording bands of the phase change marks and the wobbles in theprerecorded data zone are different from each other and are 18T (18T isone half of 36T) for the wobbles and 2T for the phase change marks, andin this regard, a CNR of 9.5 dB is obtained.

Accordingly, the CNR of the prerecorded information is equivalent to52.5 dB, and even if −2 dB is estimated as a crosstalk amount fromadjacent tracks, the CNR is equivalent to 50.5 dB. In short, a degree ofsignal quality substantially equal to that of the phase change marks isobtained, and the wobbling signal can be used appropriately forrecording and reproduction of prerecorded information.

FIG. 15 illustrates a modulation method of prerecorded information forforming a wobbled groove in the prerecorded data zone.

An FM code is used for the modulation.

Data bits are illustrated in (a) of FIG. 15; channel clocks in (b) ofFIG. 15; FM codes in (c) of FIG. 15; and wobble waveforms in (d) of FIG.15, in a vertically juxtaposed relationship.

1 bit of data is 2 ch (a 2-channel clock), and when the bit informationis “1”, the FM code is represented in a frequency of one half that ofthe channel clock.

On the other hand, when the bit information is “0”, the FM code isrepresented in a frequency equal to one half that when the bitinformation is “1”.

As regards the wobble waveform, an FM code may be recorded directly inthe form of a rectangular wave, but may otherwise be recorded in theform of a sine wave as seen in (d) of FIG. 15.

It is to be noted that the FM code and the wobble waveform may have suchpatterns as shown in (e) and (f) of FIG. 15 as the patterns of theopposite polarity to those of (c) and (d) of FIG. 15, respectively.

In such rules for FM code modulation as described above, the FM codewaveform and the wobble waveform (sine waveform) where the data bitstream is “10110010” as seen in (g) of FIG. 15 are such as shown in (h)and (i) of FIG. 15, respectively.

It is to be noted that, where the patterns shown in (e) and (f) of FIG.15 are used, the FM code waveform and the wobble waveform (sinewaveform) are such as illustrated in (j) and (k) of FIG. 15.

-   -   2-2. ECC Format of the Data

An ECC format for phase change marks and prerecorded information isdescribed with reference to FIGS. 16, 17, 18A and 18B.

First, FIG. 16 shows an ECC format for main data (user data) to berecorded and reproduced in the form of a phase change mark.

As an ECC (Error Correction Code), two codes of an LDC (long distancecode) for main data of 64 KB (=2,048 bytes of 1 sector×32 sectors) and aBIS (Burst Indicator Subcode) are available.

Main data of 64 KB illustrated in (a) of FIG. 16 is ECC encoded in sucha manner as seen in (b) of FIG. 16. In particular, an EDC (errordetection code) of 4 B is added to the main data of 1 sector of 2,048 B,and the LDC is encoded for the 32 sectors. The LDC is an RS(248, 216,33), that is, an RS (Reed Solomon) code of the code length 248, data 216and distance 33. 304 codewords are involved.

Meanwhile, for the BIS, data of 720 B shown in (c) of FIG. 16 is ECCencoded as seen in (d) of FIG. 16. In particular, the BIS is an RS(62,30, 33), that is, an RS (Reed Solomon) code of the code length 62, data30 and distance 33. 24 codewords are involved.

FIG. 18A shows a frame structure for main data in the RW zone.

The data of the LDC described above and the BIS form the frame structureshown. In particular, one frame has a structure of 155 B which includesdata (38 B), a BIS (1 B), data (38 B), a BIS (1 B), data (38 B), a BIS(1 B), data (38 B) disposed in order therein. In short, one frame isformed from data of 38 B×4=152 B and BISs of 1 B each inserted for each38 B.

A frame sync FS (frame synchronizing signal) is disposed at the top ofone frame of 155 B. One block includes 496 frames.

The LDC data are disposed such that even-numbered codewords such as 0th,2nd, . . . codewords are positioned at even-numbered frames such as 0th,2nd, . . . frames and odd-numbered codewords such as 1st, 3rd, . . .codewords are positioned at odd-numbered frames such as 1st, 3rd, . . .frames.

For the BIS, a code having a much higher correction capability than thecode of the LDC is used, and almost all errors are corrected. In short,the BIS uses a code whose distance is 33 while the code length is 62.

Therefore, a symbol of BIS from within which an error is detected can beused in the following manner.

Upon decoding of an ECC, the BISs are decoded first. If two adjacentones of the BISs and the frame sync FS in the frame structure of FIG.18A are in error, the data 38 B sandwiched between them is regarded asburst error data. An error pointer is added to the data 38 B. The LDCuses the error pointer to perform pointer erasure correction.

Consequently, the correction capability can be raised when compared withcorrection only by the LDC.

The BIS includes address information and so forth. The address is usedwhere address information by a wobbling groove is not available as inthe case of a ROM type disk or in a like case.

An ECC format for the prerecorded information is shown in FIG. 17.

In this instance, for the ECC, two codes are available including an EDC(Long Distance Code) for main data of 4 KB (1 sector 2,048 B×2 sectors)and a BIS (Burst Indicator Subcode).

Data of 4 KB as prerecorded information illustrated in (a) of FIG. 17 isECC encoded as seen in (b) of FIG. 17. In particular, an EDC (ErrorDetection Code) of 4 B is added to the main data 1 of one sector of2,048 B, and the LDC is encoded for the 2 sectors. The LDC is an RS(248,216, 33), that is, an RS (Reed Solomon) code of the code length 248,data 216 and distance 33. 19 codewords are involved.

Meanwhile, for the BIS, data of 120 B shown in (c) of FIG. 17 is ECCencoded as seen in (d) of FIG. 17. In particular, the BIS is an RS(62,30, 33), that is, an RS (Reed Solomon) code of the code length 62, data30 and distance 33. Four codewords are involved.

FIG. 18B shows a frame structure for the prerecorded information in thePB zone.

The data of the LDC described above and the BIS form the frame structureshown. In particular, one frame has a structure of 21 B which includes aframe sync FS (1 B), data (10 B), a BIS (1 B), data (9 B) disposed inorder therein. In short, one frame is formed from data of 19 B and BISof 1 B inserted in the data.

A frame sync FS (frame synchronizing signal) is disposed at the top ofone frame. One block includes 248 frames.

Also in this instance, for the BIS, a code having a much highercorrection capability than the code of the LDC is used, and almost allerrors are corrected. Therefore, a symbol of the BIS from within whichan error is detected can be used in the following manner.

Upon decoding of an ECC, the BIS is decoded first. If two adjacent onesof the BISs and the frame sync FS are in error, the data 10 B or 9 Bsandwiched between them is regarded as burst error data. An errorpointer is added to the data 10 B or 9 B. The LDC uses the error pointerto carry out pointer erasure correction.

Consequently, the correction capability can be raised when compared withcorrection only by the LDC.

The BIS includes address information and so forth. In the prerecordeddata zone, prerecorded information is recorded in the form of a wobblinggroove, and accordingly, address information by a wobbling groove is notinvolved. Therefore, an address included in the BIS is used foraccessing.

As can be seen from FIGS. 16 and 17, the data an the prerecordedinformation in the form of phase change marks adopt the same code andstructure for the ECC format.

This signifies that an ECC decoding process for the prerecordedinformation can be executed by a circuit system which performs an ECCdecoding process upon reproduction of data in the form of phase changemarks and the disk drive apparatus can improve the efficiency inhardware configuration.

2-3. Address Format

2-3-1. Relationship between Recording and Reproduction Data andAddresses

The unit in recording and reproduction of the DVR disk of the presentembodiment is a recording and reproduction cluster of totaling 498frames formed by adding a link area for a PLL and so forth of one frameto each of the top and the bottom of an ECC block of 156 symbols×496frames shown in FIGS. 18A to 18B. The recording and reproduction clusteris called RUB (Recording Unit Block).

In the address format of the disk 1 of the present embodiment, one RUB(498 frames) is managed in three address units (ADIP_(—)1, ADIP_(—)2 andADIP_(—)3) recorded as wobbles as seen in FIG. 19A. In other words, oneRUB is recorded for the three address units.

In the address format, one address unit is formed from totaling 83 bitsincluding 8 bits of a sync part and 75 bits of a data part. In theaddress format, a reference carrier signal for a wobble signal to berecorded on a pregroove is a cosine signal (Cos(ωt)), and 1 bit of thewobble signal is formed from 56 periods of the reference carrier signalas seen in FIG. 19B. Accordingly, the length of one period (1 wobbleperiod) of the reference carrier signal is equal to 69 times the lengthof one channel of phase changes. The reference carrier signal for 56periods which forms one bit is hereinafter referred to as bit block.

2-3-2. Sync Part

FIG. 20 shows a bit configuration of the sync part in the address unit.The sync part is a portion for identifying the top of the address unitand is formed from four first to fourth sync blocks (sync block “1”,sync block “2”, sync block “3” and sync block “4”). Each sync block isformed from two bit blocks including a monotone bit and a sync bit.

In a signal waveform of a monotone bit, as shown in FIG. 21A, the firstto third wobbles of the bit block formed from 56 wobbles are formed as abit synchronization mark BM, and the fourth to fifty sixth wobblesfollowing the bit synchronization mark BM are formed as monotone wobbles(a signal waveform of a reference carrier signal (Cos(ωt))).

The bit synchronization mark BM is a signal waveform generated by MSKmodulating modulation object data of a predetermined code pattern foridentifying the top of a bit block. In particular, the bitsynchronization mark BM is a signal waveform generated by differentiallycoding modulation object data of a predetermined code pattern andallocating a frequency in accordance with the sign of the differentiallycoded data. It is to be noted that the minimum code length L of themodulation object data is equal to twice the wobble period. In thepresent example, a signal waveform obtained by MSK modulating modulationobject data wherein the value for one bit (for two wobble periods) is“1” is recorded as the bit synchronization mark BM. In particular, thebit synchronization mark BM exhibits a signal waveform wherein waveformsof “Cos(1.5 ωt), −Cos(ωt), −Cos(1.5 ωt)” appear successively in a unitof the wobble period.

Accordingly, the monotone bit can be generated by generating suchmodulation object data (having a code length corresponding to 2 wobbleperiods) as “10000 . . . 00” as seen in FIG. 21B and then MSK modulatingthe modulation object data.

It is to be noted that the bit synchronization mark BM is inserted notonly into the monotone bit of the sync part but also to the top of allbit blocks described below. Accordingly, upon recording or reproduction,if the bit synchronization mark BM is detected and used forsynchronization, then synchronism of the bit blocks in the wobble signal(that is, synchronism in the period of 56 periods) can be established.Furthermore, the bit synchronization mark BM can be used as a referencefor specifying the insertion position of various modulation signalshereinafter described into the bit block.

In the signal waveform of the sync bit of the first sync block (sync “0”bit), as shown in FIG. 22A, the first to third wobbles of a bit blockformed from 56 wobbles form a bit synchronization mark BM, and the 17thto 19th wobbles and the 27th to 29th wobbles individually form an MSKmodulation mark MM while the remaining waveform of the wobbles are allmonotone wobbles.

In the signal waveform of the sync bit of the second sync block (sync“1” bit), as shown in FIG. 23A, the first to third wobbles of a bitblock formed from 56 wobbles form a bit synchronization mark BM, and the19th to 21st wobbles and the 29th to 31st wobbles individually form anMSK modulation mark MM while the remaining waveform of the wobbles areall monotone wobbles.

In the signal waveform of the sync bit of the third sync block (sync “2”bit), as shown in FIG. 24A, the first to third wobbles of a bit blockformed from 56 wobbles form a bit synchronization mark BM, and the 21stto 23rd wobbles and the 31st to 33rd wobbles individually an MSKmodulation mark MM while the remaining waveform of the wobbles are allmonotone wobbles.

In the signal waveform of the sync bit of the fourth sync block (sync“3” bit), as shown in FIG. 25A, the first to third wobbles of a bitblock formed from 56 wobbles form a bit synchronization mark BM, and the23rd to 25th wobbles and the 33rd to 35th wobbles individually form anMSK modulation mark MM while the remaining waveform of the wobbles areall monotone wobbles.

The MSK synchronization mark is a signal waveform generated by MSKmodulating modulation object data of a predetermined code patternsimilarly to the bit synchronization mark BM. In particular, the MSKsynchronization mark is a signal waveform generated by differentiallycoding modulation object data of a predetermined code pattern andallocating a frequency in response to the code of the differentiallycoded data. It is to be noted that the minimum code length L of themodulation object data is equal to twice the wobble period. In thepresent example, a signal waveform obtained by MSK modulating modulationobject data wherein the value for one bit (for two wobble periods) is“1” is recorded as the bit synchronization mark BM. In particular, thebit synchronization mark BM exhibits a signal waveform wherein waveformsof “Cos(1.5 ωt), −Cos(ωt), −Cos(1.5 ωt)” appear successively in a unitof the wobble period.

Accordingly, the sync bit of the first sync block (the sync “0” bit) canbe generated by generating and MSK modulating such a data stream (havinga code length equal to 2 wobble periods) as shown in FIG. 22B.Similarly, the sync bit of the second sync block (the sync “1” bit) canbe generated by generating and MSK modulating such a data stream asshown in FIG. 23B. The sync bit of the third sync block (the sync “2”bit) can be generated by generating and MSK modulating such a datastream as shown in FIG. 24B. The sync bit of the first sync block (thesync “3” bit) can be generated by generating and MSK modulating such adata stream as shown in FIG. 25B.

It is to be noted that the insertion pattern of the two MSK modulationmarks MM into the bit block is unique from the insertion patterns of theMSK modulation marks MM into the other bit blocks. Therefore, uponrecording and reproduction, synchronism of an address unit can beestablished by MSK demodulating the wobble signal to discriminate theinsertion pattern of the MSK modulation marks MM in the bit block anddiscriminating at least one of the four sync bits, and demodulation anddecoding of the data part described below can be performed accordingly.

2-3-3. Data Part

FIG. 26 shows a bit configuration of the data part in an address unit.The data part is a portion in which actual data of address informationis placed and is formed from 15 first to fifteenth ADIP blocks (ADIPblock “1” to ADIP block “15”). Each ADIP block includes one monotone bitand four ADIP bits.

The monotone bit has a signal waveform similar to that shown in FIG.21A. Each of the ADIP bits represents one bit of actual data, and adifferent signal waveform is exhibited depending upon the contents ofthe code of the 1 bit.

If the code contents represented by an ADIP bit are “1”, then the firstto third wobbles of the bit block formed from 56 wobbles form a bitsynchronization mark BM and the 13th to 15th wobbles form an MSKmodulation mark MM, and the 19th to 55th wobbles form a modulation partof the HMW “1” wherein Sin(2ωt) is added to the reference carrier signal(Cos(ωt)) while all the remaining wobbles have a waveform of monotonewobbles. In particular, an ADIP bit whose code contents represent “1”can be generated by generating and MSK modulating such a modulationobject data (having a code length equal to 2 wobble periods) as“100000100 . . . 00” as seen in FIG. 27B and adding Sin(2ωt) having anamplitude of −12 dB to the 19th to 55th wobbles of the signal waveformafter the MSK modulated as seen in FIG. 27C.

Where the code contents represented by an ADIP bit are “0”, the first tothird wobbles of the bit block formed from 56 wobbles form a bitsynchronization mark BM and the 15th to 17th wobbles form an MSKmodulation mark MM, and the 19th to 55th wobbles form a modulation partof the HMW “0” wherein −Sin(2ωt) is added to the reference carriersignal (Cos(ωt)) while all the remaining wobbles have a waveform ofmonotone wobbles. In particular, an ADIP bit whose code contents are “0”can be generated by generating and MSK modulating such a modulationobject data (having a code length equal to 2 wobble periods) as“100000010 . . . 00” as seen in FIG. 28B and adding −Sin(2ωt) having anamplitude of −12 dB to the 19th to 55th wobbles of the signal waveformafter the MSK modulated as seen in FIG. 28C.

As described above, the bit contents of the ADIP bits are distinguisheddepending upon the inserted position of the MSK modulation mark MM. Inparticular, if the MSK modulation mark MM is inserted in the 13th to15th wobbles, then this represents that the ADIP bit is “1”, but if theMSK modulation mark MM is inserted in the 15th to 17th wobbles, thenthis represents that the ADIP bit is “0”. Further, the ADIP bitsrepresent bit contents same as the bit contents represented by theinserted position of the MSK modulation mark MM in HMW modulation.Accordingly, since the ADIP bits represent the same bit contents in thetwo different modulation methods, decoding of data can be performed withcertainty.

A format of an address unit wherein such a sync part and a data part asdescribed above are represented compositely is shown in FIG. 29.

According to the address format of the disk 1 of the present embodiment,bit synchronization marks BM, MSK modulation marks MM and HMW modulationparts are disposed discretely in one address unit. Then, monotonewobbles for more than at least one wobble period are disposed betweenadjacent modulation signal parts. Accordingly, no interference occursbetween the modulation signals, and the individual signals can bedemodulated with certainty.

2-3-4. Contents of the Address Information

The address format of the ADIP information recorded in such a manner asdescribed above is such as illustrated in FIG. 30.

The ADIP address information includes 36 bits, and 24 parity bits areadded to them.

The ADIP address information of 36 bits includes 3 bits of a layernumber (layer no. bit 0 to layer no. bit 2) for multi-layer recording,19 bits (RUB no. bit 0 to layer no. bit 18) for a RUB (Recording UnitBlock), and 2 bits (address no. bit 0, address no. bit 1) for threeaddress blocks for 1 RUB.

Further, 12 bits are prepared for AUX data such as a disk ID in whichrecording conditions such as recording and reproduction laser powers arerecorded.

The AUX data is used for data recording of disk information hereinafterdescribed.

An ECC unit for the address data is a unit of totaling 60 bits in thismanner and is formed from 15 nibbles (1 nibble=4 bits) of Nibble 0 toNibble 14 as seen in FIG. 30.

The error correction method is the nibble-based Reed Solomon code RS(15,9, 7) wherein 1 symbol is formed from 4 bits. In short, 15 nibbles arefor the code length, 9 nibbles for the data, and 6 nibbles for theparity.

2-4. Address Demodulation Circuit

Now, an address demodulation circuit for demodulating addressinformation from a DVR disk of the address format described above isexplained.

FIG. 31 is a block diagram showing the address demodulation circuit.

Referring to FIG. 31, the address demodulation circuit 30 includes a PLLcircuit 31, an MSK timing generator 32, an MSK multiplier 33, an MSKintegrator 34, an MSK sample/hold circuit 35, an MSK slice circuit 36, aSync decoder 37 and an MSK address decoder 38. The address demodulationcircuit 30 further includes an HMW timing generator 42, an HNW multiple43, an HMW integrator 44, an HMW sample/hold circuit 45, an HMW slicecircuit 46 and an HMW address decoder 47.

A wobble signal reproduced from a DVR disk is inputted to the PLLcircuit 31. The PLL circuit 31 detects edge components from the wobblesignal inputted thereto to generate a wobble clock synchronized with thereference carrier signal (Cos(ωt)). The generated wobble clock issupplied to the MSK timing generator 32 and the HMW timing generator 42.

The MSK timing generator 32 generates a reference carrier signal(Cos(ωt)) synchronized with the wobble signal inputted thereto. Further,the MSK timing generator 32 generates a clear signal (CLR) and a holdsignal (HOLD) from the wobble clock. The clear signal (CLR) is a signalgenerated at a timing delayed by a ½ wobble period from a start edge ofa data clock of the modulation object data whose minimum code length isequal to twice the wobble period. Meanwhile, the hold signal (HOLD) is asignal generated at a timing delayed by a ½ wobble period from an endedge of the data clock of the modulation object data. The referencecarrier signal (Cos(ωt)) generated by the MSK timing generator 32 issupplied to the MSK multiplier 33. The clear signal (CLR) generated bythe MSK timing generator 32 is supplied to the MSK integrator 34. Thehold signal (HOLD) generated by the MSK timing generator 32 is suppliedto the MSK sample/hold circuit 35.

The MSK multiplier 33 multiplies the wobble signal inputted thereto bythe reference carrier signal (Cos(ωt)) to perform a synchronousdetection process. The synchronously detected output signal is suppliedto the MSK integrator 34.

The MSK integrator 34 performs an integration process for the signalsynchronously detected by the MSK multiplier 33. It is to be noted thatthe MSK integrator 34 clears its integrated value to zero at ageneration timing of the clear signal (CLR) generated by the MSK timinggenerator 32.

The MSK sample/hold circuit 35 samples the integrated output value ofthe MSK integrator 34 at a generation timing of the hold signal (HOLD)generated by the MSK timing generator 32 and holds the sampled valueuntil a next hold signal (HOLD) is generated.

The MSK slice circuit 36 binarizes the value held by the MSK sample/holdcircuit 35 using the origin (0) as a threshold value and outputs thebinarized value with the code reversed.

Then, the output signal of the MSK slice circuit 36 makes a demodulatedmodulation object data stream.

The Sync decoder 37 detects a sync bit in the sync part from a bitpattern of the demodulation data outputted from the MSK slice circuit36. The Sync decoder 37 establishes synchronism of the address unit fromthe detected sync bit. The Sync decoder 37 generates, based on thesynchronization timing of the address unit, an MSK detection windowrepresentative of the wobble position of MSK modulated data in the ADIPbits of the data part and an HMW detection window representative of thewobble position of HMW modulated data in the ADIP bits of the data part.FIG. 32A illustrates a synchronization position timing of the addressunit detected from the sync bit and FIG. 32B illustrates a timing of anMSK detection window while FIG. 32C illustrates a timing of an HMWdetection window.

The Sync decoder 37 supplies the MSK detection window to the MSK addressdecoder 38 and supplies the HMW detection window to the HMW timinggenerator 42.

The MSK address decoder 38 receives the demodulation stream outputtedfrom the MSK slice circuit 36 as an input thereto, detects the insertedposition of the MSK modulation mark MM in an ADIP bit of the demodulateddata stream based on the MSK detection window and discriminates codecontents represented by the ADIP bit. In particular, if the insertionpattern of the MSK modulation mark of the ADIP bit is such a pattern asshown in FIGS. 27A to 27C, then the code contents of the ADIP bit arediscriminated as “1”, but if the insertion pattern of the MSK modulationmark of the ADIP bit is such a pattern as shown in FIGS. 28A to 28C,then the code contents of the ADIP bit are discriminated as “0”. Then,the MSK address decoder 38 outputs a bit train obtained from a result ofthe discrimination as MSK address information.

The HMW timing generator 42 generates a second order harmonic signal(Sin(2ωt)) synchronized with the wobble signal inputted thereto from thewobble clock. Further, the HMW timing generator 42 generates a clearsignal (CLR) and a hold signal (HOLD) from the HMW detection window. Theclear signal (CLR) is a signal generated at a timing of a start edge ofthe HMW detection window. Meanwhile, the hold signal (HOLD) is a signalgenerated at a timing of an end edge of the HMW detection window. Thesecond order harmonic signal (Sin(2ωt)) generated by the HMW timinggenerator 42 is supplied to the HMW multiplier 43. The clear signal(CLR) generated by the HMW timing generator 42 is supplied to the HMWintegrator 44. The hold signal (HOLD) generated by the HMW timinggenerator 42 is supplied to the HMW sample/hold circuit 45.

The HMW multiplier 43 multiplies the wobble signal inputted thereto bythe second order harmonic signal (Sin(2ωt)) to perform a synchronousdetection process. The synchronously detected output signal is suppliedto the HMW integrator 44.

The HMW integrator 44 performs an integration process for the signalsynchronously detected by the HMW multiplier 43. It is to be noted thatthe HMW integrator 44 clears its integrated value to zero at ageneration timing of the clear signal (CLR) generated by the HMW timinggenerator 42.

The HMW sample/hold circuit 45 samples the integrated output value ofthe HMW integrator 44 at a generation timing of the hold signal (HOLD)generated by the HMW timing generator 42 and holds the sampled valueuntil a next hold signal (HOLD) is generated. In particular, since theHMW modulated data is for 37 wobbles in one bit block, if the clearsignal (HOLD) is generated at n=0 (n indicates the wobble number) asseen in FIG. 32D, then the HMW sample/hold circuit 45 samples theintegrate value at n=36 as seen in FIG. 32E.

The HMW slice circuit 46 binarizes the value held by the HMW sample/holdcircuit 45 using the origin (0) as a threshold value and outputs thecode of the binarized value.

Then, the output signal of the HMW slice circuit 46 makes a demodulateddata stream.

The HMW address decoder 47 discriminates code contents represented byeach ADIP bit from the demodulated data stream. Then, the HMW addressdecoder 47 outputs a bit train obtained from a result of thediscrimination as HMW address information.

FIGS. 33A to 33C show signal waveforms when an ADIP bit whose codecontents are “1” is HMW demodulated by the address demodulation circuit30. It is to be noted that the axis of abscissa (n) of FIGS. 33A to 33Cindicates the period number of the wobble period. FIG. 33A shows thereference carrier signal (Cos(ωt)), the modulation object data whosecode contents are “1” and a second order harmonic signal waveform(Sin(2ωt), −12 dB) formed based on the modulation object data. FIG. 33Bshows a generated wobble signal. FIG. 33C shows a synchronous detectionoutput signal (HMW×Sin(2ωt)) of the wobble signal an integrated outputvalue of the synchronous detection output signal, a hold value of theintegrated output value and demodulated modulation object data outputtedfrom the HMW slice circuit 46.

FIGS. 34A to 34C show signal waveforms when an ADIP bit whose codecontents are “0” is HMW demodulated by the address demodulation circuit30. It is to be noted that the axis of abscissa (n) of FIGS. 34A to 34Cindicates the period number of the wobble period. FIG. 34A shows thereference carrier signal (Cos(ωt)), the modulation object data whosecode contents are “1” and a second order harmonic signal waveform(−Sin(2ωt), −12 dB) formed based on the modulation object data. FIG. 34Bshows a generated wobble signal. FIG. 34C shows a synchronous detectionoutput signal (HMW×Sin(2ωt)) of the wobble signal, an integrated outputvalue of the synchronous detection output signal, a hold value of theintegrated output value and demodulated modulation object data outputtedfrom the HMW slice circuit 46.

As described above, the address demodulation circuit 30 can detectsynchronization information of an address unit recorded in an MSKmodulated form and perform MSK demodulation and HMW demodulation basedon the detection timing.

3. ECC Format of the Disk Information

In the disk of the present example, data of disk information is recordedas additional information in the form of a wobbling groove together withabsolution address information of ADIP addresses.

In particular, in the address format of an ECC unit for the ADIPinformation described above with reference to FIG. 30 includes AUX dataof 12 bits (reserve bit 0 to reserve bit 12), and the 12 bits areutilized as disk information.

The disk information is formed from, for example, 112 bytes formed bycollecting 12 bits of ECC blocks of ADIP information and includesattributes and control information of the disk as hereinafter described.

Contents of disk information recorded on the disk in advance using AUXdata (reserve bit 0 to reserve bit 12) in ADIP information are describedwith reference to FIG. 35.

FIG. 35 illustrates contents of disk information formed from 112 bytesand indicates the contents for each byte position in the 112 bytes.Further, FIG. 35 indicates the byte number (number of bytes) as a datasize of each of the contents.

In 2 bytes of the byte numbers 0 and 1, a code “DI” is recorded as anidentifier of the disk information (disc information identifier).

In 1 byte of the byte number 2, the version of the format of the diskinformation is indicated.

In 1 byte of the byte number 4, the frame number in the disk informationblock is indicated.

In 1 byte of the byte number 5, the number of frames in the diskinformation block is indicated.

In 1 byte of the byte number 6, the byte number used in the frame of thedisk information block is indicated.

In 3 bytes of the byte numbers 8 to 10, a code representative of a disktype such as a rewritable/ROM type is recorded.

In 1 byte of the byte number 11, a disk diameter such as, for example,120 mm is indicated as a disk size and a format version is indicated.

In 1 byte of the byte number 12, the number of layers of a multi-layerdisk is indicated as a disk structure.

In 1 byte of the byte number 13, a channel density, that is, a capacity,is indicated.

In 1 byte of the byte number 16, presence or absence of a BCA isindicated.

In 1 byte of the byte number 17, a maximum transfer rate of anapplication is indicated.

In 8 bytes of the byte numbers 24 to 31, the last address of the datauser are is indicated.

In 4 bytes of the byte numbers 32 to 35, a recording speed is indicated.

In 4 bytes of the byte numbers 36 to 39, a maximum DC reproduction poweris indicated.

In 4 bytes of the byte numbers 40 to 43, a maximum reproduction powerwhen high frequency modulation is applied is indicated.

In 8 bytes of the byte numbers 48 to 55, a recording power at a nominalrecording speed is indicated.

In 8 bytes of the byte numbers 56 to 63, a recording power at a maximumrecording speed is indicated.

In 8 bytes of the byte numbers 64 to 71, a recording power at a minimumrecording speed is indicated.

In 1 byte of the byte number 72, a recording multi-pulse width isindicated.

In 3 bytes of the byte numbers 73 to 75, a first recording pulse widthis indicated.

In 3 bytes of the byte numbers 76 to 78, a first recording pulseposition at the nominal recording speed is indicated.

In 3 bytes of the byte numbers 79 to 81, a first recording pulseposition at the maximum recording speed is indicated.

In 3 bytes of the byte numbers 82 to 84, a first recording pulseposition at the minimum recording speed is indicated.

In 1 byte of the byte number 88, an erase multi-pulse width isindicated.

In 3 bytes of the byte numbers 89 to 91, a first erase pulse position atthe nominal recording speed is indicated.

In 3 bytes of the byte numbers 92 to 94, a first erase pulse position atthe maximum recording speed is indicated.

In 3 bytes of the byte numbers 95 to 97, a first erase pulse position atthe minimum recording speed is indicated.

In 1 byte of the byte number 98, a flag bit representative of thepolarity of an erase pulse is recorded.

The bytes other than those of the byte numbers given above are allreserved.

Such disk information as described above is recorded at least in the RWzone in the lead-in zone described hereinabove with reference to FIG.13.

While the inner circumference side of the lead-in zone is formed as a PBzone and has prerecorded data recorded therein, the RW zone into andfrom which data can be recorded and reproduced in accordance with thephase change recording method is formed next to the PB zone. Recordingof absolute addresses (recording in the form of a wobbling groove) asADIP information is started at the top of the RW zone. Together with theADIP addresses, the disk information is recorded using the AUX data(reserve bit 0 to reserve bit 12) in the ADIP information.

Since the lead-in zone is a region which is accessed first when the diskis loaded into a disk drive apparatus, where disk information isrecorded at least in the lead-in zone, the disk drive apparatus cansuitably read in such various kinds of information as describedhereinabove with reference to FIG. 35.

It is to be noted that, since the ADIP information is recorded similarlyalso in the data zone, also it is possible to record the diskinformation making use of bits as the AUX data into the data zone. Inshort, the disk information having the configuration described above maybe recorded repetitively over the overall area of the RW zone.

For the error correction method for the ADIP information, the nibblebased Reed Solomon code RS(15, 9, 7) is described wherein 1 symbol isformed from 4 bits as described hereinabove in connection with the ECCblock format of FIG. 30.

For the address information, it is sufficient to use only such an errorcorrection coding method as described above due to the characteristicthat the address information is recorded successively on a disk and itdoes not make a serious problem even if some error occurs therewith.

On the other hand, for the disk information, a higher level errorcorrection method than that for the address information is requiredbecause the disk information includes information which makes areference upon recording and reproduction onto and from the disk 1.

Therefore, in the present example, for the disk information, higherlevel error correction coding (coding according to a first errorcorrection method) is performed first, and then the disk information isallocated as AUX data (reserve bit 0 to reserve bit 12) to the ADIPformat. Accordingly, disk information to be recorded as ADIP data isfirst subject to coding according to the first error correction method,and then subject to coding according to a second error correction methodof the nibble based Reed Solomon code RS(15, 9, 7) so that an ECC blockof the ADIP information of 60 bits may be formed. Consequently, dualerror correction coding is applied to the disk information.

Furthermore, in the present example, coding similar to error correctioncoding for user data which is recorded and reproduced in accordance withthe phase change recording method is applied to the error correctioncoding for the disk information so that a higher error correctioncapability may be obtained.

The error correction coding method for user data (main data) has beendescribed hereinabove with reference to FIG. 16. In particular, for userdata of 64 KB, the RS(248, 216, 33), that is, the RS (Reed Solomon) codeof the code length 248, data 216 and distance 33, is used for the LDC.

FIG. 36 illustrates an LDC in the form of data of 216 bytes and a parityof 32 bytes as a 1 ECC codeword of 248 bytes.

Also for the disk information, the RS(248, 216, 33), that is, the RS(Reed Solomon) code of the code length 248, data 216 and distance 33, isused similarly for the LDC. FIG. 37 shows the ECC format for the diskinformation.

The AUX data is formed from 12 bits for 1 ADIP word (the format of FIG.30), in short, from 1.5 bytes.

A frame (DI frame) of the disk information is formed from 96 ADIPs, thatis, from 144 bytes.

The information amount of the disk information of 1 DI frame is 112bytes as seen in FIG. 35.

To the 112 bytes, 104 bytes of data “FFh (=11111111)” are added as dummydata to obtain data of 216 bytes.

FIG. 37 shows an ECC format wherein a parity of 32 bytes is added to thedata of 216 bytes.

In this instance, the data is an RS code of the code length 248, data216, distance 33 and parity 32.

In short, the ECC format is an ECC format according to the LDC (longdistance code) same as that for user data described hereinabove withreference to FIG. 16.

By this, the disk information becomes data having a high level errorcorrection capability similar to that for user data, and consequently,the reliability is augmented.

Further, the disk information is incorporated into ADIP information andformed as data for reproduction only which is recorded in the form of awobbling groove, and since it is not recorded in the form of embosspits, it is suitable for a high density disk like the presentembodiment.

Further, in a disk drive apparatus, there is no necessity to provide anew circuit system for an error correction process upon reproduction ofthe disk information. This is because the circuit section for performingan error correction process for user data can be used commonly.

Furthermore, the dummy data need not be recorded on the disk 1. Inparticular, when an error correction process is performed upon errorcorrection coding or upon reproduction, 104 bytes of the dummy data“FFh” may be added to 1 ECC code.

Therefore, the number of symbols to be recorded on the disk 1 can bereduced and the recording linear density can be increased to raisereliability or the recording capacity can be increased.

4. Disk Drive Apparatus

Now, a disk drive apparatus which can record/reproduce such a disk 1 asdescribed above is explained.

FIG. 38 shows a configuration of the disk drive apparatus.

The disk 1 is placed onto a turntable not shown and is driven to rotateat a constant linear velocity (CLV) by a spindle motor 52 uponrecording/reproduction operation.

Then, ADIP information (address and disk information) embedded aswobbling of groove tracks in the RW zone on the disk 1 is read out by anoptical pickup (optical head) 51. Further, prerecorded informationembedded as wobbling of groove tracks in the PB zone is read out.

Further, upon recording, user data is recorded as phase change marks ona track in the RW zone by the optical pickup, but upon reproduction, therecorded phase change marks are read out by the optical pickup.

In the optical pickup 51, a laser diode serving as a laser light source,a photodetector for detecting reflected light, an objective lens servingas an output end of the laser light, and an optical system (not shown)for illuminating the laser light upon a disk recording face through theobjective lens and introducing the reflected light from the diskrecording face to the photodetector are formed.

The laser diode outputs a blue laser beam of a wavelength of 405 nm. TheNA by the optical system is 0.85.

In the pickup 51, the objective lens is supported for movement in atracking direction and a focusing direction by a two-axis mechanism.

Further, the entire pickup 51 is supported for movement in a disk radiusdirection by a thread mechanism 53.

The laser diode in the pickup 51 is driven with a drive signal (drivecurrent) from a laser driver 63 to emit laser light.

Reflected light information from the disk 1 is detected and convertedinto an electric signal corresponding to an amount of received light bythe photodetector and is supplied as the electric signal to a matrixcircuit 54.

The matrix circuit 54 includes a plural number of current to voltageconversion circuits, matrix operation/amplification circuits and soforth corresponding to output current from a plurality of lightreception elements of the photodetector. The matrix circuit 54 thusgenerates necessary signals through a matrix operation process.

For example, the matrix circuit 54 generates a high frequency signal(reproduction data signal) corresponding to reproduction data, afocusing error signal and a tracking error signal for servo control, andso forth.

Furthermore, the matrix circuit 54 generates a push-pull signal as asignal relating to wobbling of a groove, that is, as a signal fordetecting wobbling.

The reproduction data signal outputted from the matrix circuit 54 issupplied to a reader/writer circuit 55 while the focusing error signaland the tracking error signal are supplied to a servo circuit 61, andthe push-pull signal is supplied to a wobble circuit 58.

The reader/writer circuit 55 performs a binarization process, areproduction clock production process by a PLL and so forth for thereproduction data signal to reproduce data read out from phase changemarks and supplies the generated data to a modulation/demodulationcircuit 56.

The modulation/demodulation circuit 56 includes a functioning section asa decoder upon reproduction and another functioning section as anencoder upon recording.

Upon reproduction, the modulation/demodulation circuit 56 performs ademodulation process of a runlength limited code based on are areproduction clock as a decoding processing.

An ECC encoder/decoder 57 performs an ECC encoding process for adding anerror correction code upon recording and an ECC decoding process forperforming error correction upon reproduction.

Upon reproduction, the ECC encoder/decoder 57 fetches data demodulatedby the modulation/demodulation circuit 56 into an internal memory andperforms an error detection/correction process, a deinterleaving processand so forth to obtain reproduction data.

The ECC encoding process and the ECC decoding process by the ECCencoder/decoder 57 are processes ready for the ECC format wherein theRS(248, 216, 33), that is, the RS (Reed Solomon) code of the code length248, data 216 and distance 33, is used.

Data decoded up to reproduction data by the ECC encoder/decoder 57 isread out based on an instruction of a system controller 60 andtransferred to an AV (Audio-Visual) system 120.

The push-pull signal outputted as a signal relating to wobbling of thegroove from the matrix circuit 54 is processed by the wobble circuit 58.The push-pull signal as ADIP information is MSK demodulated and HMWdemodulated into data stream which represents ADIP addresses by thewobble circuit 58 and is supplied to an address decoder 59.

The address decoder 59 performs decoding of the data supplied thereto toobtain an address value and supplies the address value to the systemcontroller 60.

Further, the address decoder 59 performs a PLL process using the wobblesignal supplied thereto from the wobble circuit 58 to generate a clockand supplies the clock as an encoding clock, for example, upon recordingto the pertaining sections.

The wobble circuit 58 and the address decoder 59 have, for example, aconfiguration described hereinabove with reference to FIG. 31.

The address decoder 59 performs an error correction process using thenibble based Reed Solomon code RS(15, 9, 7) corresponding to the ECCformat shown in FIG. 30.

The address value supplied to the system controller 60 as describedabove has undergone the error correction process.

Meanwhile, the disk information recorded using AUX data is extracted 12bits by 12 bits from 1 ECC block (ADIP word) by the address decoder 59and supplied to the ECC encoder/decoder 57.

The ECC encoder/decoder 57 adds dummy data of 104 bytes to 144 B of the96 ADIP words shown in FIGS. 27A to 27C to generate 1 ECC codeword andperforms ECC decoding using the RS(248, 216, 33), that is, the RS (ReedSolomon) code of the code length 248, data 216 and distance 33, toobtain error corrected disk information which can be supplied to thesystem controller 60.

Meanwhile, the push-pull signal outputted as a signal relating towobbling of the groove from the matrix circuit 54, that is, a push-pullsignal as the prerecorded information from the PB zone, undergoes abandpass filter process by the wobble circuit 58 and is supplied to thereader/writer circuit 55. Then, the push-pull signal is binarized andconverted into a data bit stream similarly as in the case of phasechange marks, and is then ECC decoded and deinterleaved by the ECCencoder/decoder 57 to extract data of the prerecorded information. Theextracted prerecorded information is supplied to the system controller60.

The system controller 60 can perform various setting processes, a copyprotection process and so forth based on the read out prerecordedinformation.

Upon recording, recording data is transferred from the AV system 120 tothe disk drive apparatus. The recording data is sent to-and bufferedinto a memory of the ECC encoder/decoder 57.

In this instance, the ECC encoder/decoder 57 performs addition of errorcorrection codes, interleave and addition of subcodes and so forth as anencoding process of the buffered recording data.

Further, the ECC encoded data is modulated in accordance with theRLL(1-7) PP method by the modulation/demodulation circuit 56 and thensupplied to the reader/writer circuit 55.

As an encoding clock which is used as a reference clock for suchencoding processes upon recording, the clock generated from the wobblesignal as described above is used.

The recording data generated by the encoding process is subject to fineadjustment of an optimum recording power, adjustment of a laser drivepulse waveform and so forth suitable for a characteristic of therecording layer, the spot shape of a laser beam, a recording linearspeed and so forth as recording compensation processing by thereader/writer circuit 55. Then, the recording data is sent as a laserdrive pulse to the laser driver 63.

The laser driver 63 provides the laser drive pulse supplied thereto tothe laser diode the pickup 51 to drive the laser diode to emit laserlight. As a result, a pit (phase change mark) corresponding to therecording data is formed on the disk 1.

It is to be noted that the laser driver 63 includes an APC circuit (AutoPower Control) and controls the laser diode so that the output power ofthe laser may be fixed independently of the temperature and so forthwhile monitoring the laser output power based on an output of a laserpower monitoring detector provided in the optical pickup 51. Targetvalues for the laser output power upon recording and upon reproductionare provided from the system controller 60, and upon recording and uponreproduction, the thread mechanism 53 controls the laser diode so thatthe laser output power level may have the target values, respectively.

The servo circuit 61 generates various servo drive signals for focusing,tracking and threading from the focusing error signal and the trackingerror signal from the matrix circuit 54 so that servo operations may beexecuted.

In particular, the servo circuit 61 generates a focusing drive signaland a tracking drive signal based on the focusing error signal and thetracking error signal respectively, and drives a focusing coil and atracking coil of the two-axis mechanism in the optical pickup 51 withthe focusing drive signal and the tracking drive signal, respectively.Consequently, a tracking servo loop and a focusing serve loop are formedfrom the pickup 51, matrix circuit 54, servo circuit 61 and two-axismechanism.

Further, the servo circuit 61 turns off the tracking servo loop inaccordance with a track jumping instruction from the system controller60 and outputs a jumping drive signal so that a track jumping operationmay be executed.

Furthermore, the servo circuit 61 generates a thread drive signal basedon a thread error signal obtained as a low frequency component of thetracking error signal and access execution control and so forth from thesystem controller 60 to drive the thread mechanism 53. Though not shown,the thread mechanism 53 includes a mechanism formed from a main shaftfor supporting the optical pickup 51, a thread motor, a transmissiongear and so forth and drives the thread motor in accordance with thethread drive signal to perform a required sliding movement of theoptical pickup 51.

A spindle servo circuit 62 performs control for rotating the spindlemotor 52 at a CLV.

The spindle servo circuit 62 acquires the clock generated by a PLLprocess for the wobble signal as current rotational speed information ofthe spindle motor 52 and compares the rotational speed information withpredetermined CLV reference speed information to generate a spindleerror signal.

Upon data reproduction, since the reproduction clock (clock which makesa reference to a decoding process) generated by a PLL in thereader/writer circuit 55, the spindle servo circuit 62 can compare thereproduction clock with predetermined CLV reference speed information togenerate a spindle error signal.

Then, the spindle servo circuit 62 outputs a spindle drive signalgenerated in response to the spindle error signal so as to execute CLVrotation of the spindle servo circuit 62.

Further, the spindle servo circuit 62 generates a spindle drive signalin accordance with a spindle kick/brake control signal from the systemcontroller 60 so as to perform such operations as starting, stopping,acceleration and deceleration of the spindle motor 52.

Such various operations of the servo systems and recording andreproduction system as described above are controlled by the systemcontroller 60 formed from a microcomputer.

The system controller 60 executes various processes in accordance with acommand from the AV system 120.

For example, when a writing instruction (write command) is issued fromthe AV system 120, the system controller 60 causes the pickup 51 to moveto an address that is to be written first. Then, the system controller60 controls the ECC encoder/decoder 57 and the modulation/demodulationcircuit 56 to execute an encoding process as described above for data(video data and/or audio data of the various types such as, for example,MPEG2 data and so forth) transferred thereto from the AV system 120.Then, a laser drive pulse is supplied from the reader/writer circuit 55to the laser driver 63 as described above so that recording is executed.

Further, for example, if a read command for demanding transfer ofcertain data (MPEG2 video data or the like) recorded on the disk 1 isreceived from the AV system 120, then seek operation control isperformed setting the designated address as an object. In particular, aninstruction is issued to the servo circuit 61 first so that the servocircuit 61 executes an accessing operation of the pickup 51 setting anaddress designated by a seek command as a target.

Thereafter, operation control necessary to transfer data in thedesignated data section to the AV system 120 is performed. Inparticular, the system controller 60 first performs readout of data fromthe disk 1 and controls the reader/writer circuit 55,modulation/demodulation circuit 56 and ECC encoder/decoder 57 to performdecoding/buffering and so forth to transfer the demanded data.

It is to be noted that, upon recording or reproduction of data in theform of phase change marks, the system controller 60 performs control ofaccessing, recording and reproduction operations using an ADIP addressdetected by the wobble circuit 58 and address decoder 59.

Further, at a predetermined point of time such as when the disk 1 isloaded, the system controller 60 controls so as to execute readout of aunique ID recorded in the BCA of the disk 1 or of prerecordedinformation recorded as a wobbling groove in the prerecorded data zonePR.

In this instance, the system controller 60 performs seek operationcontrol toward the BCA or the prerecorded zone PR first. In particular,the system controller 60 issues an instruction to the servo circuit 61to execute an accessing operation of the pickup 51 to the innermostcircumference side of the disk.

Thereafter, the system controller 60 controls the pickup 51 to executereproduction tracing to obtain a push-pull signal as reflected lightinformation and controls the wobble circuit 58, reader/writer circuit 55and ECC encoder/decoder 57 to execute a decoding process to obtainreproduction data as BCA information or prerecorded information.

The system controller 60 performs a laser power setting process, a copyprotect process and so forth based on the BCA information or theprerecorded information read out in this manner.

It is to be noted that, upon reproduction of prerecorded information,the system controller 60 performs control of an accessing orreproduction operation using address information included in a BIScluster as the read out prerecorded information.

Further, after prerecorded information is read out, the disk informationincorporated in and recorded together with the ADIP information in thesection of the RW zone in the lead-in zone can be read out and used fora required process.

Incidentally, while the example of FIG. 38 is a disk drive apparatusconnected to the AV system 120, the disk drive apparatus of the presentembodiment may be connected, for example, to a personal computer or thelike.

Furthermore, the apparatus of the present invention may be used also ina form wherein it is not connected to any other apparatus. In thisinstance, an operation section or a display section may be provided, orthe configuration of an interface section for inputting and outputtingdata may be different from that of FIG. 38. In short, only it isnecessary for the apparatus to perform recording or reproduction inresponse to an operation of a user and include a terminal sectionprovided for inputting and outputting various data therethrough.

Naturally, various other configurations may be possible, and forexample, the apparatus may be configured as an apparatus only forrecording or an apparatus only for reproduction.

5. Disk Production Method

Subsequently, a production method of the disk 1 of the presentembodiment described above is described.

The production process of a disk can be roughly divided into a masteringprocess and a disk formation process (replication process). Themastering process is a process until a metal master (stamper) to be usedin the disk formation process is completed, and the disk formationprocess is a process of producing an optical disk of a replica of thestamper in a mass using the stamper.

More particularly, in the mastering process, so-called mastering whereinphoto-resist is applied to a polished glass substrate and a pit or agroove is formed on the photosensitive film by exposure to a laser beamis performed.

In the case of the present example, mastering of a groove by wobblingbased on prerecorded information is performed at a portion of the diskcorresponding to the PB zone on the innermost circumference side, andmastering of a groove by wobbling based on ADIP address information anddisk information is performed at a portion corresponding to the RW zone.

The prerecorded information and the disk information to be recorded areprepared in a preparation step called premastering.

Then, after the mastering comes to an end, predetermined processes suchas development are performed, and then transfer of the information tothe metal surface is performed, for example, by electroforming togenerate a stamper necessary to perform replication of the disk.

Thereafter, the stamper is used to transfer the information to a resinsubstrate, for example, by an injection method or the like, and areflection film is formed on the resin substrate, whereafter such aprocess as working of the resin substrate into a required disk form tocomplete a final product.

The mastering apparatus includes, for example, as shown in FIG. 39, aprerecorded information generation section 71, a prerecorded ECCencoding section 72, a changeover section 73, a mastering section 74, adisk information generation section 75, an address generation section76, a disk information ECC encoding section 77, a synthesis section 78,an address ECC encoding section 79 and a controller 70.

The prerecorded information generation section 71 outputs prerecordedinformation prepared by the premastering step. The outputted prerecordedinformation is subject to an error correction coding process by theprerecorded ECC encoding section 72. For example, ECC encoding in whichthe RS(248, 216, 33), that is, the RS (Reed Solomon) code of the codelength 248, data 216 and distance 33, is used may be performed similarlyas in the case of the disk information.

The disk information generation section 75 generates information of 112bytes of the contents described hereinabove with reference to FIG. 35.The generated disk information of 112 bytes is subject to addition ofdummy data of 104 bytes thereto and ECC encoding by the RS(248, 216, 33)with a parity of 32 bytes, that is, the RS (Reed Solomon) code of thecode length 248, data 216 and distance 33 as described hereinabove withreference to FIG. 37 by the disk information ECC encoding section 77.

The address generation section 76 successively outputs values ofabsolute addresses.

The synthesis section 78 synthesizes address values outputted from theaddress generation section 76 and the disk information which has beenECC encoded by the disk information ECC encoding section 77. Inparticular, the synthesis section 78 successively generates data of 9nibbles (36 bits) of an ADIP word of the format of FIG. 30. In short,the synthesis section 78 incorporates the ECC encoded disk informationas AUX data in the ADIP word. It is to be noted that the dummy data partillustrated in FIG. 37 having been added by the disk information ECCencoding section 77 may not be incorporated as AUX data.

Then, the address ECC encoding section 79 performs error correctioncoding using the nibble based Reed Solomon code RS(15, 9, 7) to form anECC block of the format illustrated in FIG. 30.

The mastering section 74 includes an optical section (82, 83, 84) forilluminating a laser beam upon a glass substrate 101 having photo-resistapplied thereto to perform mastering, a substrate rotation/feedingsection 85 for driving the glass substrate 101 to rotate and slidablyfeeding the glass substrate 101, and a signal processing section 81 forconverting input data into recording data and supplying the recordingdata to the optical section. The mastering section 74 further includes asensor 86 for discriminating from the position of the substraterotation/feeding section 85 in which one of the PB zone and the RW zonethe mastering position is.

The optical section described above includes a laser light source 82formed from, for example, a He—Cd laser, a modulation section 83 formodulating light emitted from the laser light source 82 based onrecording data, and a mastering head part 84 for condensing andilluminating the modified beam from the modulation section 83 upon thephoto-resist face of the glass substrate 101.

The modulation section 83 includes an acousto-optic type opticalmodulator (AOM) for turning on/off the light emitted from the laserlight source 82, and an acousto-optic type optical deflector (AOD) fordeflecting the light emitted from the laser light source 82 inaccordance with a wobble production signal.

The substrate rotation/feeding section 85 includes a rotary motor fordriving the glass substrate 101 to rotate, a detector (FG) for detectingthe speed of rotation of the rotary motor, a slide motor for slidablymoving the glass substrate 101 in a radial direction, and a servocontroller for controlling the rotational speeds of the rotary motor andthe slide motor, tracking of the mastering head part 84 and so forth.

The signal processing section 81 performs a modulation signal productionprocess of performing predetermined operation processes, for example,for prerecorded information supplied thereto through the changeoversection 73 and ADIP information including disk information and addressinformation to form a modulation signal.

The signal processing section 81 performs also a driving process fordriving the optical modulator and the optical deflector of themodulation section 83 in accordance with the modulation signal.

In the mastering section 74, upon mastering, the substraterotation/feeding section 85 drives the glass substrate 101 to rotate ata constant linear velocity and slidably move the glass substrate 101while the glass substrate 101 remains rotated so that spiral tracks maybe formed in a predetermined track pitch.

Simultaneously, the light emitted from the laser light source 82 isconverted into a modulated beam based on the modulation signal from thesignal processing section 81 by the modulation section 83 and isilluminated upon the photo-resist face of the glass substrate 101 fromthe mastering head part 84. As a result, the photo-resist is sensitizedbased on the data or groove.

The controller 70 controls execution of operation of the masteringsection 74 upon such mastering and controls the prerecorded informationgeneration section 71, disk information generation section 75, addressgeneration section 76 and changeover section 73 while supervising thesignal from the sensor 86.

Upon starting of mastering, the controller 70 controls the substraterotation/feeding section 85 to set the slidably moved position of thesubstrate rotation/feeding section 85 to its initial position so thatthe mastering head part 84 may start illumination of the laser beam uponthe mastering section 74 from the innermost circumference side. Then,the controller 70 controls so as to start CLV rotational driving of theglass substrate 101 and slidable feeding of the glass substrate 101 forforming a groove of a track pitch of 0.35 μm.

In this state, the controller 70 controls the prerecorded informationgeneration section 71 to output prerecorded information so that theprerecorded information may be supplied to the signal processing section81 through the changeover section 73. Further, the controller 70controls the laser light source 82 to start outputting of a laser beam,and the modulation section 83 modulates the laser beam in accordancewith a modulation signal from the signal processing section 81, that is,an FM code modulation signal of the prerecorded information, to executegroove mastering on the glass substrate 101.

Consequently, mastering of such a groove as described hereinabove withreference to FIG. 14B is performed in a region corresponding to the PBzone.

Thereafter, when the controller 70 detects from the signal of the sensor86 that the mastering operation has proceeded to a positioncorresponding to the terminal end of the PB zone, it changes over thechangeover section 73 to the address ECC encoding section 79 side andinstructs the address generation section 76 to successively output anaddress value. Further, the controller 70 instructs the disk informationgeneration section 75 to generate disk information.

Further, the controller 70 controls the substrate rotation/feedingsection 85 to lower the sliding feeding speed so that a groove having atrack pitch of 0.32 μm may be formed.

Consequently, ADIP information including the address information and thedisk information is supplied from the address ECC encoding section 79 tothe signal processing section 81 through the changeover section 73.Then, the laser light from the laser light source 82 is modulated withthe modulation signal from the signal processing section 81, that is,based on MSK modulation and HMW modulation, by the modulation section83, and groove mastering of the glass substrate 101 is executed with themodulated laser light.

Consequently, mastering of such as described hereinabove with referenceto FIG. 14A is performed for a region corresponding to the RW zone.

The controller 70 ends the mastering operation if it detects from asignal of the sensor 86 that the mastering operation reaches theterminal end of the lead-out zone.

Through such operations as described above, light exposure partscorresponding to the wobbling groove as the PB zone and the RW zone areformed on the glass substrate 101.

Thereafter, development, electroforming and so forth are performed togenerate a stamper, and the disk 1 described hereinabove is producedusing the stamper.

The produced disk 1 is a disk wherein the ADIP information including thedisk information is recorded in the form of a wobbling groove in the RWzone as described hereinabove.

While the disk of the embodiment and the disk drive apparatus and thedisk production method for the disk have been described above, thepresent invention is not limited to them, but various modifications canbe made within the scope of the present invention.

While, in the example described above, user data is recorded as phasechange marks, the recording method for user data may be any rewritableor write-once-read-many method. For example, the present invention canbe applied also to a disk or a disk drive apparatus ready for arecording method such as, for example, a photo-electric recording methodor a pigment changing method.

As can be recognized from the foregoing description, the disk recordingmedium of the present invention or a disk recording medium produced bythe disk production method of the present invention is configured suchthat the disk recording medium has a recording and reproduction regioninto and from which first data can be recorded and reproduced inaccordance with a rewritable or write-once-read-many recording methodand from which second data recorded in the form of wobbling of a groovecan be reproduced, and that the second data includes address informationand additional information and the additional information is coded inaccordance with a first error correction method, and the codedadditional information and the address information are recorded in astate coded in accordance with a second error correction method.

Thus, since additional information such as properties of the disk isrecorded in the form of a wobbling groove together with addressinformation and recording in the form of emboss pits is not used, goodrecording of the additional information can be executed for a highdensity disk. Further, since the additional information is errorcorrection coded dually in accordance with the first and second errorcorrection methods, the reliability thereof as information is very high.

Further, since the first error correction method used for the additionalinformation is same as that used for the first data which is principaldata, an error correction code adopted for principal data and having avery high correction capability can be used as the first errorcorrection method, and the reliability of the additional information canbe improved. Furthermore, in the disk drive apparatus, an errorcorrection encoding/decoding section ready for the first errorcorrection method can be used so to function as an error correctiondecoding section (additional information decoding means) for theadditional information and further as an error correctionencoding/decoding section for the first data to be recorded andreproduced. In other fords, the hardware for performing the errorcorrection/coding processes can be used commonly, and simplification inconfiguration and reduction in cost can be anticipated.

Further, since the additional information to be recorded on the diskrecording medium adds, to the additional information of a unit of msmaller than a code length n in error correction coding of the firstdata, m-n dummy data to perform error correction coding for the datahaving a code length equal to n, an error correction method similar tothat used for the first data can be used for the additional information.Further, since the dummy data is added upon error correction coding anderror correction decoding, the number of symbols to be recorded onto thedisk recording medium can be reduced. Consequently, the recording lineardensity can be increased and the reliability can be raised. Further, thecapacity for recording can be increased.

From the foregoing, the present invention can achieve a significanteffect that it is preferable for a disk recording medium of a largecapacity and also the performance in recording and reproductionoperation of a disk drive apparatus can be improved.

1. A disk recording medium comprising: a recording and reproductionregion into and from which first data can be recorded and reproduced inaccordance with a rewritable or write-once-read-many recording methodand from which second data recorded in the form of wobbling of a groovecan be reproduced, wherein the second data includes address informationand additional information and the additional information is coded inaccordance with a first error correction method, and the codedadditional information with the address information added are recordedin a state coded in accordance with a second error correction method. 2.A disk recording medium according to claim 1, wherein the first errorcorrection method is same as the error correction method used for thefirst data.
 3. A disk recording medium according to claim 2, wherein theadditional information is error correction coded such that, to theadditional information of a unit of m smaller than a code length n inerror correction coding of the first data, m-n dummy data are added soas to have a code length equal to n.
 4. A disk recording mediumaccording to claim 1, wherein the additional information is recorded atleast in a lead-in zone in the recording and reproduction region.
 5. Adisk production method for a disk recording medium having a recordingand reproduction region into and from which first data is to be recordedand reproduced in accordance with a rewritable or write-once-read-manyrecording method, said disk production method comprising the steps of:generating second data by coding additional information in accordancewith a first error correction method and coding the coded additionalinformation with added address information in accordance with a seconderror correction method; and forming the recording and reproductionregion by spirally forming a groove wobbled based on the second data. 6.A disk production method according to claim 5, wherein the first errorcorrection method is same as the error correction method used for thefirst data.
 7. A disk production method according to claim 6, whereinthe additional information is error correction coded such that, to theadditional information of a unit of m smaller than a code length n inerror correction coding of the first data, m-n dummy data are added soas to have a code length equal to n.
 8. A disk production methodaccording to claim 5, wherein the additional information is recorded atleast in a lead-in zone in the recording and reproduction region.
 9. Adisk drive apparatus which performs recording or reproduction onto orfrom a disk recording medium which has a recording and reproductionregion into and from which first data can be recorded and reproduced inaccordance with a rewritable or write-once-read-many recording methodand from which second data recorded in the form of wobbling of a groovecan be reproduced, the second data including address information andadditional information, the additional information being coded inaccordance with a first error correction method, the coded additionalinformation with the address information added being recorded in a statecoded in accordance with a second error correction method, said diskdrive apparatus comprising: readout means for reading out the seconddata from the wobbled groove of the disk recording medium; addressdecoding means for performing error correction decoding in accordancewith the second error correction method for the second data read out bysaid readout means to obtain the address information and the additionalinformation coded in accordance with the first error correction method;and additional information decoding means for performing errorcorrection decoding in accordance with the first error correction methodfor the additional information coded in accordance with the first errorcorrection method and obtained by said address decoding means.
 10. Adisk drive apparatus according to claim 9, wherein the first errorcorrection method is same as the error correction method used for thefirst data, and said additional information decoding means furtherperforms error correction decoding and error correction coding for thefirst data.
 11. A disk drive apparatus according to claim 10, whereinsaid additional information decoding means adds, to the additionalinformation of a unit of m smaller than a code length n in errorcorrection coding of the first data, m-n dummy data to perform errorcorrection decoding for the data having a code length equal to n.
 12. Adisk drive apparatus according to claim 9, wherein the additionalinformation is obtained from the second data read out from a lead-inzone in the recording and reproduction region by said readout means.